JPS6145094B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an automatic transmission for a vehicle, and more particularly to a gear position detection device for a vehicle transmission suitable for use in an automatic transmission. Recently, automatic vehicles have been developed and put into practical use in automobiles, especially passenger cars. In such an automatic vehicle, for example, when the shift lever is shifted from the N range (neutral position) to the D range (drive position) in order to start the vehicle, the clutch is automatically turned off, and then the transmission is turned off. First gear is selected. When the accelerator pedal is depressed from this state, the amount of depression of the accelerator pedal is detected, the clutch is automatically turned on, and the vehicle starts moving. Furthermore, in such an automatic vehicle, gear shifting operations are performed automatically while the vehicle is running. That is, the electronic control unit built into the automatic vehicle stores automatic shift line patterns for the D range, first range, and second range of the shift lever. If an operating point enters each of the first, second, and third speed regions defined by the automatic shift line pattern from another region, this is detected and a shift operation is automatically performed. The automatic transmission for this type of automatic vehicle is a combination of an automatic clutch and an automatic transmission, and various types have been developed, but some are a combination of a torque converter and a planetary gear type transmission. are mainly used. However, planetary gear type transmissions have a complicated structure and require a lot of effort to assemble. Moreover, the structure of this planetary gear type transmission is different from the conventional manually operated parallel shaft gear type transmission.
The existing production line cannot be used, and a new production line must be used. Therefore, it has the disadvantage that it is more expensive than a parallel shaft gear type transmission. For this reason, the present inventors devised and filed an application for a transmission drive device that can use a parallel shaft gear type transmission. According to this proposal, an electric motor and a rod are used to drive a parallel shaft gear type transmission, which has the advantage of a simple structure and easy control. On the other hand, in such an automatic transmission, it is necessary to detect and output the position of the gear changed, and display it on an indicator or use it for controlling the emission control circuit, etc. Conventionally, in order to detect the gear position, multiple switches were installed in the transmission control box, the switches were operated by the movement of the shift rod, and the switch output was used as the gear position detection output, but it is not possible to provide multiple switches separately. In addition to the drawbacks of complicating the structure and not being able to achieve a low-cost configuration, there is also the drawback that it becomes a load on the operation of the shift rod, leading to an increase in the driving force of the transmission drive device. Therefore, it is an object of the present invention to provide a gear position detection device for an automatic transmission that is inexpensive and has a simple configuration and can detect the gear position without causing a load on the shift rod by utilizing the configuration of the electric motor. There is something to do. Hereinafter, the present invention will be explained in detail with reference to the drawings. Fig. 1 is a block diagram of the transmission drive device that is the basis of the present invention, Fig. 2 is a block diagram of the parallel shaft gear type transmission used in the configuration shown in Fig. 1, and Figs. FIG. 5 is a perspective view of a main part, and is an explanatory diagram of the operation of the drive device shown in FIG. 1. In FIG. 1, reference numerals 1 and 1' indicate DC motors, which have a worm 11 at the tip of a shaft 10 surrounded by an armature 12, as shown in FIG. 2 and 2' are gear boxes disposed adjacent to the motors 1 and 1', respectively; 21 and 21' are disposed within the gear boxes and are rotatably supported around a rotating shaft 22; The worm gear meshes with the gear 11, and has a movable contact 23 on its wheel surface, and the movable contact 23 is connected to the ground potential G by a fixed contact 24, and has a fixed position corresponding to the rotation angle of the gear 21. Corresponding to the wall of box 2, there is a neutral contact 27, a right position contact 29, and a left position contact 2.
8, a right plate contact 25 and a left plate contact 26 are provided. Returning to Fig. 1, 3 and 3' are arm mechanisms, and as shown in Fig. 3 a, the worm gear 21
The arm 31 has a ball joint 32 attached to its tip, and the tip of the arm 31 (ball joint 32) moves in an arc. Reference numerals 4 and 4' designate connecting rods, and as shown in FIG. A pin 43 and a U-shaped pin support 42 are provided. The connecting rod 4' has an engaging hole 4 at one end that engages with the ball joint 32' of the arm mechanism 3', as shown in Figure 1c.
1', and an engagement hole 42' for engaging with the ball joint 62 of the shift lever 6 is provided at the other end, and a relay rod 5 is provided in the middle of the rod 4'. Incidentally, the rod 4 may be integrated with the relay rod 5. As shown in the perspective view of FIG. 4, the relay rod 5 is provided with a pair of cylindrical L-shaped slide rods 52 and 53 in a tube 50, and springs are attached to the L-shaped engaging portions of the slide rods 52 and 53. 54 are provided, the slide rods 52,
53 are given a force such that they repel each other. The rod 4' is screwed to the end of each slide rod 52, 53, respectively. Note that snap springs 51 and 55 are attached to the slide rods 52 and 53, respectively, and the tube 50
prevents it from coming off. Returning to FIG. 1, 6 is a shift lever, 7 is a transmission control box, and 8 is a select lever, the details of which are shown in FIG. 2. Figure 2 shows the configuration of the transmission mechanism of a well-known parallel shaft gear type transmission, in which the shift lever 6 has a ball joint 62 at its tip.
The other end is connected to the shift lever shaft 70. An internal lever 71 is attached to the shift lever shaft 70, and the internal lever 71 is connected to shift blocks 72, 7, which will be described later.
3,74. On the other hand, select lever 8
The middle part is attached to the rotating shaft 82, and the tip part 83 has the shift lever shaft 7 as shown in FIG. 2b.
A pin 84 is provided which engages with the groove 71 of 0. Further, shift blocks 72, 73, 74 that engage with the internal lever 71 are fixed to the three shift rods 75, 76, 77, respectively, and a shift fork 78 that engages with a clutch sleeve (not shown) is fixed to the shift rod 77. installed. The same applies to the other shift rods 75 and 76.
In the shift pattern of Fig. 2c, the horizontal direction of the figure is the shift direction, the vertical direction is the select direction,
Let the center be the neutral position "N". For example, to change gears to 1st gear position "1", -1 in the select direction (leftward) and -1 in the shift direction.
Therefore, when the select lever 81 is rotated in one direction (leftward) and the shift lever 61 is rotated in one direction (leftward), the end 83 of the select lever 81 is rotated. The shift lever shaft 70 is moved in the axial direction by the pin 84, and the internal lever 71 is moved toward the shift block 7.
4. As the shift lever 61 rotates, the shift lever shaft 70 rotates, and therefore the internal lever 71 also rotates, so that the shift block 74 engaged with the internal lever 71 moves in the axial direction of the shift rod 77. For this reason,
Shift rod 77 also moved and shift fork 7
8 and a clutch sleeve (not shown) to change gears. In the transmission configured in this manner, 1 is a select drive motor for driving the select lever 8, and 1' is a shift drive motor for driving the shift lever 6. To explain the operation of the transmission with this configuration, when the transmission gear is determined according to the shift pattern as shown in Fig. 2c, a rotation command is issued depending on whether the selection direction is right or left, and the selection drive Motor 1 rotates forward or backward. As a result, the worm gear 2 is connected to the worm gear 2 via the worm 11 of the motor shaft 10.
1 rotates to cause the arm 31 to move in an arc, and the ball joint 32 causes the rod 4 to move in a straight line.
The arm 31 and the rod 4 constitute a rotational-linear motion conversion mechanism. The linear motion of the rod 4 causes the select lever 81 to rotate, and the pin 84 of the select lever 81 moves the shift lever shaft 70 in the axial direction to move the internal lever 71 to the selected position of the shift blocks 72, 73, 74. block. On the other hand, similarly, a rotation command is generated corresponding to whether the shift direction is right or left, and the shift drive motor 1' rotates forward or backward. As a result, the worm gear 2 is connected to the worm gear 2 through the worm 11' of the motor shaft 10'.
1' rotates to cause the arm 31' to move in an arc, and the ball joint 32' causes the rod 4' to move in a straight line. The arm 31' and the rod 4' constitute a rotational-linear motion conversion mechanism. Relay rod 5 is attached to rod 4'.
intervening, the linear force of the rod 4' is applied to the shift lever 6 via the spring 54 of the relay rod 5.
is transmitted to. Since this spring 54 is a buffer spring that acts in both directions, the load transmitted to the shift lever 6 side is regulated within a certain range, and unreasonable force is not applied to the gear moved by the shift fork 78. This prevents the shift drive motor 1' from locking and burning due to the load of the lever 6. Further, the relay rod 5 may be provided on the selection side rod 4. When the shift lever 61 rotates, the internal lever 71
rotates and one of the shift blocks 72, 73, 74 moves in the axial direction of the shift rod, so the shift arm is moved and the desired clutch sleeve is moved to complete the gear shifting operation. Now, in the rotation of the aforementioned motors 1 and 1',
It is necessary to control the rotation angle according to the required amount of rotation of each lever 6, 8. This is done by the contact mechanism shown in Figure 3b. This operation will be explained in conjunction with the explanatory diagram of FIG. The movable contact 23 has neutral, left, and right position contacts 27 and 2.
8 and 29, a left plate track 23b for the left plate contact 26, a right plate track 23c for the right plate contact 25, and a ground track 23d for the ground contact 24.
3a is one island, plate tracks 23b, 23
C has two islands, and the grounding track 23d has a single island-shaped conductive pattern spanning half the circumference, and these conductive patterns are connected together and are always grounded by a grounding contact 24. Figure 5a
are the fixed contacts 24, 25, 26, 27, 28, 2 when the select lever 8 is in the neutral state.
9 and the movable contact 23 are shown, and the motor 1
indicates a non-driven state. That is,
Both terminals of motor 1 are grounded by relays RL1 and RL2. At this time, since only the neutral contact 27 is on the conductive pattern of the movable contact 23,
The neutral contact 27 is grounded, and the other fixed contacts 25, 26, 28, and 29 are not grounded. Here, when a rightward (positive direction) rotation command is given,
Relay RL2 turns on and relay RL2 of motor 1
Since the side contacts are connected to the power source E, the motor 1 rotates, the gear 21 rotates clockwise, and only the light position contact 29 is on the conductive pattern of the movable contact 23 as shown in FIG. 5b, i.e. When only the right position contact 29 is grounded, it stops and becomes the final position of clockwise rotation as shown in FIG. 5b. Conversely, when a counterclockwise rotation command is given, relay RL1 is turned on and the relay RL1 side contact of motor 1 is connected to power supply E, so motor 1 rotates in the reverse direction and gear 21 rotates to the left, as shown in Fig. 5c. Only the left position contact 28 is the movable contact 2.
It stops at a position on the No. 3 conductive pattern, that is, a position where only the left position contact 28 is grounded, and the No. 5
This is the final position of left rotation as shown in Figure c. A drive circuit for such drive will be explained with reference to FIG. In the figure, LS is a switch for counterclockwise rotation command, NS is a switch for neutral position command,
RS indicates a switch for commanding clockwise rotation; 90,
Reference numerals 91 and 92 indicate command transmission circuits having the same configuration, and reference numerals 94 and 95 indicate relay drive circuits having the same configuration. 96 is a neutral holding circuit, 97
is a reset circuit. This operation will be explained based on the waveform diagram in FIG. It is assumed that the rotation is made from the right rotation position shown in FIG. 5b to the left rotation position shown in FIG. 5c. (See Figure 7a) When the counterclockwise rotation command switch LS is turned on, the transistor TR1 of the transmission circuit 90 is turned on, and the relay RL3 is turned on (attracted). Therefore, the contact _rl3 of relay RL3 switches as shown by the dotted line. Therefore, voltage Ve applied from switch LS is applied to one end of relay RL1 via contact _rl3 of relay RL3. On the other hand, the voltage Ve is also applied to the relay drive circuit 94 through the contact rl ₃ , and the transistor TR2 is turned on after a time delay determined by the time constant circuit of the resistors R ₁ and C ₁ has elapsed. Therefore, transistor TR2
As shown in the figure, the collector of transistor TR3, that is, the base of transistor _TR3 , is at a high level after rl3 is turned on until transistor TR2 is turned on. During this period, transistor TR3 is turned on, and relay RL is turned on.
1 is turned on, the wires are connected as shown in FIG. 5c, and the motor 1 rotates to the left. When the motor 1 rotates, the worm gear 21,
That is, the movable contact also rotates, and therefore rotates counterclockwise from the state shown in FIG.
The potential of becomes the ground potential. Until the potential of this LG26 becomes the ground potential, the above-mentioned transistor
Since TR3 needs to be kept on, the time delay period of the time constant circuit described above is required until LG26 comes into contact with the conductive plate. By grounding LG26, the other end of relay RL1 is grounded, so even if transistor TR3 is turned off, current flows in the order of relay RL1 - LG26 - movable contact 23 - ground contact 24, so relay RL1 is driven. Leave it alone. Therefore, the motor 1 continues to rotate. When the motor 1 rotates and approaches the neutral position shown in FIG.
Before coming off, the neutral contact (NP) 27 contacts the conductive pattern. Therefore, the ground potential of NP27 is
Through the diode _D1 of 6, the transistor TR6
is transmitted to. As a result, a current flows through the route of contact rl ₃ - diode D ₂ - transistor TR6 base - transistor TR6 emitter - diode D ₁ -NP27, turning on transistor TR6. By turning on transistor TR6,
Relay RL1 is diode _D3 , transistor TR
6. The route for diode D ₁ and NP27 is secured. Even if motor 1 rotates and LG26 is removed from the conductive pattern, the route of rl ₃ - RL1 - diode D ₃ - transistor TR6 - diode D ₁ - NP27 is maintained, so relay RL1 continues to be driven and motor 1 continues to rotate. here
The time during which NP27 is in contact with the conductive pattern (i.e. the width of the island of position track 23a) is LG2.
6 is greater than the time during which the conductive pattern is not in contact (ie, the width between the islands of the left plate track 23b). Motor 1 rotates further and neutral contact 2
Even if 7 is removed from the conductive pattern or the route of is released, the left plate contact LG26 is connected to the conductive pattern, so the route of relay RL1-LG26-movable contact 23-ground contact 2
Route 4 is restored again, relay RL1 continues to be driven, and motor 1 continues to rotate. As the motor 1 rotates further and approaches the left rotation position of FIG. 5c, the left position contact (LP) 28 engages the conductive pattern before the LG 26 is removed from the conductive pattern, and LP 28 is grounded.
As a result, the diode of the reset circuit 97
The emitter of transistor TR8 is also grounded via _D4 . On the other hand, the base current of transistor TR8 is supplied through the route of switch LS - resistor R ₂ - resistor R ₃ - base of transistor TR8, but when motor 1 is rotating, voltage E applied to motor 1 is relay RL1 or relay RL
Since the transistor TR10 is turned on through the diode _D5 or _D6 , the current flowing to the base of the transistor TR8 flows to the transistor TR10, and the transistor TR8 is turned off. When the motor 1 further rotates and the LG 26 comes off the conductive pattern, the grounding of the LG 26 and the corresponding route are also released, so the relay RL1 returns and the motor 1 stops. This position is shown in Figure 5c. On the other hand, as relay RL1 returns,
The base voltage E of the transistor TR10 is no longer supplied, and the transistor TR10 is turned off. As a result, current flows into the base of the transistor TR8 via the resistors R ₂ and R ₃ .
Transistor TR8 turns on. The collector of the transistor TR8 is connected to the resistor R ₄ of the transmission circuit 90,
Since it is connected to the midpoint of _R5 , transmission circuit 9
0, bypasses the base current of transistor TR1, turns off transistor TR1, and turns off the relay.
Restore RL3. In the manner described above, the rotation from the right position in FIG. 5b to the left position in FIG. 5c is completed. Conversely, for rotation from the left position in FIG. 5c to the right position in FIG. 5b, the right rotation command switch RS is turned on and the same operation is performed. That is, 'as mentioned above,
Similarly, turn on relay RL5 of transmission circuit 92,
Furthermore, transistor TR4 of relay drive circuit 95 is turned on, relay RL2 is turned on, and motor 1 is rotated clockwise. 'Next, the light plate (RG) 25 is grounded and the relay RL2-RG
25-movable contact 23-ground contact 24 route, relay RL2 is kept on, and motor 1 continues to rotate. 'Next, with the operation of the neutral contact (NP) 27 in the same way as in , the contact rl ₅ - diode D ₇
- Transistor TR6 - Diode D ₁ - Transistor TR6 turns on through the route of NP27, and relay RL
Relay RL2 is kept on through the route 2-diode _D8 -transistor TR6-diode _D1 -NP27. 'Relay RL2- again as same as next
The holding route of RG25 is restored and relay RL2 continues to be on. ’, the write position contact (RP) 29 is grounded, but the transistor TR9
is turned off, and RG25 is removed from the conductive pattern in the same way as in the case of FIG. 'Further, similarly to the above, the transistor TR10 is turned off, the transistor TR9 is turned on, the transistor of the transmission circuit 92 is turned off, and the relay RL5 is reset. In this way, the circuit from the left position in FIG. 5c to the right position in FIG. 5b is completed. Next, the rotation from the right rotation position shown in FIG. 5b to the neutral position shown in FIG.
(see figure b). In this case, the rotation is counterclockwise, so turn on the counterclockwise rotation command switch LS and the neutral switch NS. When the switch LS is turned on, the above-mentioned operations are performed. On the other hand, since switch NS is on, relay RL is
4 is turned on, and transistor TR5 is turned on. For this reason, the transistor TR6 is always off, and the holding route of is not established. Therefore, without performing the following operations described above, the relay RL1 is grounded by releasing the grounding of LG26 at the neutral position shown in Figure 5a.
returns and motor 1 stops. Since NP27 is grounded in the neutral position of FIG. 5a, the emitter of transistor TR7 is grounded via diode _D10 . Here, switch NS is on, so transistor TR7 is on,
The emitter of transistor TR8 is also grounded. When the relay RL1 is restored, the transistor TR10 is turned off, so the transistor TR8 is turned on, turning off the transistor TR1 of the transmission circuit 90 and restoring the relay RL3. Conversely, from the neutral position in Figure 5a to Figure 5c
Since the rotation to the counterclockwise position requires counterclockwise rotation, turn on the counterclockwise rotation command switch LS and perform the above-mentioned ~
Perform the following actions. Since the next operation does not occur because it starts from the neutral position, it jumps to the operation, executes the operation, and stops at the counterclockwise rotation position. To summarize the above, the transmission circuit 90 or 91 is
and connect relay RL1 or RL2 to rl ₃ -RL1-
Turns on at the first route of TR3 or rl ₅ - RL2 - TR4, rotates motor 1, and when motor 2 rotates, LG
26 or RG25 is grounded, rl ₃ −RL1−
The relay RL1 or RL2 is kept on in the second route of LG26 or _RL5 -RL2-RG25, and the motor 1 is rotated. Furthermore, for rotation across the neutral position, rl ₃ −RL1− at grounding of NP27.
TR6-NP27 or rl ₅ -RL2-TR6-NP27
The relay RL1 or RL2 is kept on on the third route, and then the second route is returned to rotate the motor 1 further. And LG26 or RG2
5 to release the ground, the second route is released, and motor 1
At the same time, the reset circuit 97 is activated by grounding LP28 or RP29, and the transmission circuit 90
Or reset relay RL3 or RL5 of 92.
To stop at the neutral position, contact NS is turned on, relay RL4 is operated, and operation of holding circuit 96 is prohibited to prevent the formation of the third route.
Therefore, when LG26 or RG25 is grounded, motor 1 stops at the neutral position, and when NP27 is grounded, transistor TR7 is turned on, transistor TR8 or TR9 is turned on, and relay RL3 or RL5 of transmission circuit 90 or 92 is reset. It is something that makes you In the above explanation, the motor 1 of the selector lever 8
The same applies to the motor 1' of the shift lever 6. However, the left and right position contacts 28' of the motor 1' of the shift lever 6,
If 29' is provided at a wide angle position of 90 degrees or more (preferably 120 degrees) with respect to the neutral position 27', in the final position, the shift lever 6 from the motor 1
The load on the clutch sleeve becomes zero, and there is no need to apply extra force to the clutch sleeve after gear engagement. In a transmission drive device that performs such an operation, the rotation of the worm gears 21, 21' is the same as actually operating the rod and driving the shift lever 6 and select lever 8, so the rotation of the worm gears 21, 21' By detecting the position, it is possible to detect the drive of the internal lever 71 by the shift lever 6 and the select lever 8, that is, the gear position. For this reason, the gears 21 and 21' may be provided with a separate rotational position detection means for gear detection, but referring to FIGS. The output of 29 can be used to detect the gear position. That is, the neutral contact 27 contacts the conductive pattern of the movable contact 23 only in the neutral position of FIG. 5a, and is grounded as NP 27 of FIG. 7b. Conversely, the left position contact 28 contacts the movable contact 23 only at the left rotation stop position shown in FIG.
It is grounded like LP28 in Figure 7a. Further, the write position contact 29 contacts the movable contact 23 and is grounded only at the right rotation stop position shown in FIG. 5b. This includes not only the worm gear 21 that operates the select lever 8 mentioned above, but also the contacts 27' at each position on the worm gear 21' that operates the shift lever 6.
The same applies to 28' and 29'. Therefore, these position contacts 27, 28, 29, 27', 28',
By using the output of 29', a gear position detection output can be generated. FIG. 8 shows a control circuit according to an embodiment of the present invention, with each position contact 27, 28, 29, 27', 2
The gear position detection output is generated from the outputs of 8' and 29'. The control circuit 100 is composed of nine NOR circuits R1 to R9, and the outputs of the respective position contacts 27, 28, and 29 on the select side are input terminals.
Received by SA ~ SC, each position contact 27' on the shift side,
Receive the outputs of 28' and 29' at input terminals SD to SF, and output each gear detection output "1st" (1st gear), "2nd"
(2nd gear), "3rd" (3rd gear), "4th" (4th gear), "5th" (5th gear), "REV" (back gear), "N" (neutral), "N1" (neutral) and "N2" (neutral). This output corresponds to the shift pattern of FIG. 2c. The NOR circuit has 2 input terminals, 1
It has an output terminal, and when both inputs are at "0" level (ground potential), it generates a "1" level output (detection output), otherwise it generates a "0" level output. do. The connection relationship with each input terminal is as shown in the table below.

[Table] Therefore, a gear position detection output can be generated according to the rotational position of the worm gears 21, 21'. These outputs are provided to an indicator display circuit to provide an indication of gear position. It is also supplied to and used by the emission control circuit. As explained above, according to the present invention, a movable contact is provided on the gear of the motor that drives the shift lever and select lever of the transmission via the rod, and the right rotation position contact and the neutral position correspond to the rotational position of the worm gear. A position contact and a counterclockwise rotation position contact are provided, and a control circuit is provided that outputs an output indicating the gear position based on the output of each position contact, so the structure is simple and inexpensive, and it does not place a load on the shift rod. Therefore, there is an advantage that no extra driving force is required and an inexpensive and small motor can be used. Furthermore, since the electric motor is used to drive the transmission mechanism of the inexpensive parallel shaft gear type transmission, the entire transmission can be constructed at a lower cost. Although the present invention has been described using one example, the present invention is not limited to this example, and various modifications are possible within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention. isn't it.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a transmission drive device that is the basis of the present invention, Fig. 2 is an explanatory diagram of a transmission mechanism of a parallel shaft gear type transmission used in the configuration shown in Fig. 1, and Fig. 3 is an example of the configuration shown in Fig. 1. FIG. 4 is a configuration diagram of the relay rod of the configuration example in FIG. 1, FIG. 5 is an explanatory diagram of the operation of the configuration in FIG. FIG. 7 shows a waveform diagram of each part of FIG. 6, and FIG. 8 shows a circuit diagram of an embodiment of the present invention. In the figure, 1, 1'... motor, 2, 2'... gear box, 3, 3'... arm mechanism, 4, 4'... rod, 5... relay rod, 6... shift lever,
8... Select lever, 21, 21'... Worm gear, 54... Buffer spring, 71... Internal lever, 72, 73, 74... Shift block, 75, 76, 77... Shift rod, 7
8...Shift arm, 79...Gear, 23...Movable contact, 25, 26...Plate contact, 27...
Neutral contacts, 28, 29...Fixed position contacts, 100...Control circuit.

Claims (1)

[Scope of Claims] 1. An automatic transmission in which a shift lever and a select lever that drive an internal lever are each connected to a rod, and each rod is driven by a motor-driven gear to change gears, the gear being driven by a motor. A movable contact is provided for each of the gears, and a right rotation position contact, a neutral position contact, and a left rotation position contact are provided corresponding to the rotational position of the gear, and the movable contact and the three positions correspond to the rotational position of the gear. A gear position detection device for an automatic transmission, comprising a control circuit that receives an output from a position contact due to contact of the contact and generates an output indicating a gear position. 2. Gear position detection of an automatic transmission according to claim 1, wherein the position contact is connected to a drive circuit of the motor, and the drive of the motor is controlled according to the output of the position contact. Device.